Q: I've been diagnosed with temporal arteritis and am being treated with a drug called prednisone, which the doctor says is a steroid. I know athletes use steroids to bulk up, and I can't see how that would have anything to do with temporal arteritis. Can you explain?
A: I understand your confusion.
The word steroid encompasses a large group of chemicals, each of which has very different effects on the body. Plants and animals contain hundreds of different kinds of steroids. Cholesterol, estrogen, testosterone — they're all steroids. Every steroid has a basic chemical structure that contains four rings of carbon atoms, but there are many variations beyond those four basic rings. Different steroids can have very different effects on the body because of those variations.
The steroids that athletes (and athlete wannabes) use and abuse to get stronger are anabolic steroids. They're called anabolic because anabolism is the constructive aspect of metabolism — the metabolism that builds cells and tissues. (Catabolism is the deconstructive counterpart.) The anabolic steroids have muscle-building effects similar to that of natural testosterone.
The type of steroid you're taking is called a glucocorticoid, which is often altered slightly to corticosteroid. Corticosteroids are synthetic versions of the hormones produced by the outer layer, or cortex, of the adrenal glands. The cortico in corticosteroid comes from cortex. Corticosteroids are powerful anti-inflammatories and are used to treat diseases caused by an overactive immune system.
In temporal arteritis, cells of the immune system attack arteries in your head (including your brain). This attack causes pain and sometimes redness and swelling around the temporal arteries, which lie beneath the skin just above and to the side of your eyes. Treatment with corticosteroids reliably reduces the pain and swelling of the temporal arteries. It may prevent a more serious symptom — sudden blindness — that comes from the immune system attacking arteries deeper inside the head.